The present invention relates to a disk apparatus, and more particularly, a disk apparatus which simultaneously operates a plurality of functions for recording and reproducing.
Conventionally, it is required that a disk apparatus consume a small amount of power and generate a small amount of heat. A magneto-optic disk drive satisfies this requirement and is used as a back-up memory for a computer.
A conventional magneto-optic disk drive is comprised of a disk motor, a controller, an optical pickup, an actuator movement motor, a magnetic field generation function means, and a motor control system, and is controlled by commands of a host computer. The disk motor rotates a magneto-optic disk. The controller controls each function of the disk apparatus, and the optical pickup shapes a laser beam.
Such a conventional disk apparatus is operated in any of the following three states: first, the apparatus operates only at its interface with the host computer; second, the disk motor and focusing and tracking servomechanism are operated to record and reproduce; and lastly, the disk motor and focusing and tracking servomechanism are operated, but are on stand-by because no command for recording and reproducing is entered. Each of the above operating states is controlled by commands given by the host computer by way of the controller to shift from one operating state to another.
Generally speaking, from the view point of power consumption, the disk apparatus of a conventional type consumes power when all the functions work, and does not do so when all the functions are on stand-by. It should be noted that when the apparatus is on stand-by, the disk motor and focusing and tracking servomechanism are operated and thus, the disk drive consumes power. In such a case, power is consumed even if no recording or reproducing is carried out, and large average power is consumed. Also, the temperature will rise due to heat generated in the apparatus.